//
// Created by 吴锐 on 2022/3/3.
//

#include "iostream"

using namespace std;

void test01(){
    negate<int> n;
    cout << n(50) << endl;
}

void test02(){
    plus<int> p;
    cout << p(10, 20) << endl;
}

int main(){
    test01();
    test02();
    return 0;
}